Description:
A breccia pipe is a vertical, pipe-like mass of
broken rock (breccia), typically a few tens of meters
across and hundreds of meters in vertical extent.
Breccia pipes formed within Paleozoic and Triassic
strata over a broad area around the Grand Canyon, and
some contain high-grade uranium ore (Wenrich and
Titley, 2008). They were created when groundwater
(possibly basin brines), flowing through Redwall
Limestone dissolution breccias and along fracture
zones, dissolved more limestone, causing collapse
of overlying rocks and possibly creating sink holes.
Some pipes extend many hundreds of meters upward
into the Chinle Group (formerly Chinle Formation;
Heckert and Lucas, 2003), indicating that some pipes
are at least as young as this Upper Triassic rock unit
(Brown and Billingsley, 2010). Some pipes are blind
and never broke through to the surface. Breccia pipes
are abundant in the Grand Canyon region, with at
least 1300 pipes or suspected pipes identified (Sutphin
and Wenrich, 1989; Brown and Billingsley, 2010).
These breccia pipes have been of interest both for
their economic value and because they are adjacent to
Grand Canyon National Park and the Colorado River
(Spencer and Wenrich, 2013).